A stable luminescent zinc-organic framework as a dual-sensor toward Cu2+ and Cr2O72-, and excellent platform-encapsulated Ln(3+) for systematic color tuning and white-light emission

摘要

A stable, luminescent zinc-organic framework (MOF) [Zn(OBA)(2)(PTD)center dot 2DMF center dot 2H(2)O](n) (1; H(2)OBA = 4,4 '-oxybis(benzoic acid), PTD = 6-(pyridin-4-yl)-1,3,5-triazine-2,4-diamine) was synthesized using a V-shaped, carboxylate H(2)OBA ligand containing conjugated pi-moieties and a rigidly auxiliary N-rich PTD ligand, which displayed a 3D, three-fold interpenetrated framework with highly thermal and chemical stabilities. Complex 1 exhibited a strong luminescent emission, and could selectively detect Cu2+ and Cr2O72-, making it a potential dual functional chemosensor. Furthermore, the systematic explorations of lanthanide(iii) cation encapsulation for compound 1 suggested that Ln(3+)-doped compounds are good candidates as color-tunable and barcoded materials. Moreover, by soaking this as-synthesized MOF (50 mg) into a 10 mL DMF solution containing 5 x 10(-5) mmol Ln(3+) ions (Eu3+/Tb3+, 13/7), the white light-emission of the Ln(3+)-doped compound 1 was realized with the Commission Internationale de L'Eclairage coordinates (0.3095, 0.2945). The quantum yield of this white light-emitting sample is 29%, which is higher than those of most reported doped MOFs with white light-emission. Furthermore, compound 1 exhibited a selective gas capture for CO2 over CH4.